The present invention relates to a microfilming apparatus, and more particularly to an apparatus for microfilming a multiplicity of document sheets one after another and recording on the film image data, such as frame numbers assigned to the respective document sheets and blip marks, for example for retrieving the photographed images later.
Conventionally, document sheets are photographed along with frame numbers, blip marks or like data items using a data recording display on a document support portion and photographing the data on the display together with the document sheet. The film is then immediately wound up.
However, in the case where the means for photographing document sheets on a film is provided with automatic exposure control means to assure a proper exposure in microfilming, the duration of operation of the photographing means varies with the brightness of document sheets, whereas the data recording display has a given brightness and therefore produces variations in the density of recorded data. This drawback may be overcome, for example, by varying the brightness of the display in corresponding relation to the variation in the operating time of the photographing means, but this requires a complex mode of control and efficient data recording means.